Aim: The biotic resistance hypothesis argues that complex plant and animal communities are more resistant to invasion than simpler communities. Conversely, the biotic acceptance hypothesis states that non-native and native species richness are positively related. Most tests of these hypotheses at continental scales, typically conducted on plants, have found support for biotic acceptance. We tested these hypotheses on both amphibians and reptiles across Europe and North America. Location: Continental countries in Europe and states/provinces in North America. Methods: We used multiple linear regression models to determine which factors predicted successful establishment of amphibians and reptiles in Europe and North America, and additional models to determine which factors predicted native species richness. Results: Successful establishment of amphibians and reptiles in Europe and reptiles in North America was positively related to native species richness. We found higher numbers of successful amphibian species in Europe than in North America. Potential evapotranspiration (PET) was positively related to non-native species richness for amphibians and reptiles in Europe and reptiles in North America. PET was also the primary factor determining native species richness for both amphibians and reptiles in Europe and North America. Main conclusions: We found support for the biotic acceptance hypothesis for amphibians and reptiles in Europe and reptiles in North America, suggesting that the presence of native amphibian and reptile species generally indicates good habitat for non-native species. Our data suggest that the greater number of established amphibians per native amphibians in Europe than in North America might be explained by more introductions in Europe or climate-matching of the invaders. Areas with high native species richness should be the focus of control and management efforts, especially considering that non-native species located in areas with a high number of natives can have a large impact on biological diversity.